Paper patching advise needed

Discussions of powders, bullets and loading information.

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gunlaker
Posts: 2764
Joined: Tue Jun 23, 2009 6:16 pm

Re: Paper patching advise needed

Post by gunlaker »

One of the things I have often read here, and other places, is that bore diameter PP bullets don't work with smokeless.

I've never tried it and that statement sounds reasonable, however in 2001 Michael Petrov (RIP) who was a well known single shot rifle aficionado, wrote an article titled "Understanding the Paper Patched Bullet". He wrote that bore diameter PP bullets can work with smokeless and displays a ten shot 100 yard group shot with a .38-55 using 330gr bore diameter PP bullets that appears to be about a minute of angle. His powder charge was 17.0gr of 4227.

So although there are probably lots of ways the combo doesn't work, there is at least one way that it does seem to work. Of course not to many of us shoot at 100 yards, I can't remember ever shooting a group at 100 with my BPCR rifles, but Michael's load must be bumping that bullet up nicely to shoot that well.

Chris.
Jeff Michel
Posts: 34
Joined: Thu Jul 01, 2021 5:31 am

Re: Paper patching advise needed

Post by Jeff Michel »

This is the exact thing I do not understand. My 40-65 and Shiloh 45-70 is working just fine with patch to bore bullets and smokeless powder. Unless it's as Mr. McDowell/ MartiniBelgian pointed out, a larger chamber dimension is exacerbated by the use of smokeless. Haven't had an opportunity to try a patch to groove yet but I have managed to scare up a pound of fake black powder and a one pound can of FFG Goex. Maybe have enough at least to test your respective theories. Thanks for the ideas and thoughts, they were very helpful and greatly appreciated.
gunlaker
Posts: 2764
Joined: Tue Jun 23, 2009 6:16 pm

Re: Paper patching advise needed

Post by gunlaker »

I think chamber dimensions can make a big difference. When I started shooting bore diameter PP bullets it was with a C. Sharps 1874 in .45-2-7/8". It shot pretty well, but only if I used some sort of lube cookie. I believe that this was because the rifle had a pretty fat chamber with a small amount of freebore. I think it needed the lube cookie to get a good seal.

I sold that rifle and my only .45-2-7/8" is a Shiloh bull barrel rifle. It has a well cut chamber with no excessive clearance at the case mouth. It shoots well with either lube cookies or plain LDPE wads, although I generally use Kenny Wasserburgers wad stack in it. It is less picky and easier to find an accurate load. I think that's entirely due to the better chamber.

Chris.
martinibelgian
Posts: 1609
Joined: Thu Oct 26, 2006 1:20 pm

Re: Paper patching advise needed

Post by martinibelgian »

Mann's "The bullet's flight" mentions this too - accordingt o him, the ideal bullet with BP was bore diameter, but with smokeless a larger section at the rear was needed to provide the initial resistance required. At least, that's how I remember it.
But I beleive the inmportant one is the 'initial resistance'. If you don't have enough to expand your bullet, you're in trouble...
gunlaker
Posts: 2764
Joined: Tue Jun 23, 2009 6:16 pm

Re: Paper patching advise needed

Post by gunlaker »

martinibelgian wrote: Wed May 25, 2022 8:47 am Mann's "The bullet's flight" mentions this too - accordingt o him, the ideal bullet with BP was bore diameter, but with smokeless a larger section at the rear was needed to provide the initial resistance required. At least, that's how I remember it.
But I beleive the inmportant one is the 'initial resistance'. If you don't have enough to expand your bullet, you're in trouble...
I have a copy of his book that was annotated by Happy Pope. He made remarks on the paragraph where Mann mentioned this, but Pope's handwriting is completely illegible. Too bad because I'd have enjoyed seeing his comments. I'll bet I can decipher less than half of them :-).

At some time I want to try and reproduce Michael Petrov's results, but it's not very high on my list of things to do.

Chris.
beltfed
Posts: 1962
Joined: Sun Jun 03, 2007 10:07 am
Location: Central Wi

Re: Paper patching advise needed

Post by beltfed »

re. Mann .
"for smokeless a larger base diameter was required to provide more resistance."
"I believe the large base band for smokeless loading is because the more progressive burning of smokeless
does not reliably bump up a bore diameter bullet to seal the bore-resulting in gas cutting, etc.
Actually same story for BP loading if you want to go to harder -as in Antimony containing- bullets that will not have the ogive slump.
That is the advantage of the dual diameter bullets with a freebore/groove diameter base band that does not need to bump up to seal
against blowby and gas cutting. The dual diameter concept applies to GG as well as DDEPP bullets.
beltfed/arnie
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